1. Field of the Invention
The present invention relates to an image reading apparatus having a multi-crop function.
2. Description of the Related Art
There has been known a multi-crop function in which, in the case where small size originals, such as business cards, postcards, or photos, are to be read, multiple originals are placed on an original table and scanned and read in batch to crop an image corresponding to each original. There has also been known an image reading apparatus having such multi-crop function.
For example, there has been proposed an apparatus which detects the number of originals and their respective positions by pre-scan, scans the originals one by one, and displays how many originals have been scanned before the currently-scanned original, so as to enable a user to recognize an image reading state (see Japanese Unexamined Patent Publication No. 2003-219085, for example). There has also been proposed an apparatus that controls the order of cropping an image according to the original size of a cropped image, the position of the original, a size of a printing sheet used to print the original, and the type of the printing sheet, even if originals of different sizes and different types are simultaneously placed (see Japanese Unexamined Patent Publication No. 2007-013378, for example). There has also been proposed an apparatus that compares the input number of originals and the detected number of originals, and displays the comparison result, in order to correctly detect the number of images that the user desires to crop and to read these images (see Japanese Unexamined Patent Publication No. 2007-020122, for example).
All of the above publications describe that pre-scan is executed before reading originals in order to detect the size and position of each original. Such kind of image reading apparatuses are common to a scanner for personal use. On the other hand, digital multifunction peripherals for office use have recently been widespread. These digital multifunction peripherals are required to have higher working efficiency than those for personal use. To this end, such a multifunction peripheral has been commercially available that it has high reading speed and includes an original size detection unit detecting a size of an original placed on an original table without performing pre-scan. Note that such multifunction peripheral is supposed to detect a size of a single standard size original placed at a predetermined position on the original table by the original size detection unit. The standard size indicates A5 size, A4 size, A3 size, and the like in regions where sizes in AB series are popular, such as in Japan and Europe. In Japan, B5 size and B4 size are also often used. In regions where sizes in inch series are popular such as in United States and Australia, the standard size indicates 5.5×8.5 inch, 8.5×11 inch, 8.5×14 inch, and 11×17 inch.
A reading-area from which an image of an original is to be read is determined on the basis of the original size detected by the original size detection unit. When a multi-crop function is used, an area to be cropped has to be determined by detecting a size and position of each original. However, in general, the original size detection unit does not have detection capability adapted to the multi-crop function, and therefore, the original size detection unit is highly likely to detect incorrect original size.